Referring to FIG. 1, a conventional lens assembly includes a lens barrel 1, a plurality of lenses 2 that are mounted in the lens barrel 1, a plurality of light-shielding members 3 that are mounted among the lenses 2, and a retaining ring 4 for retaining the lenses 2 in the lens barrel 1. The lenses 2 are disposed in sequence from an object side 101 toward an image side 102 of the conventional lens assembly. For achieving better retainment of the lenses 2 relative to the lens barrel 1, after the retaining ring 4 is mounted in the lens barrel 1 in a position proximate to the image side 102, a plurality of adhesive elements 5 are disposed at an interconnection area between the retaining ring 4 and the lens barrel 1 in an adhesive-dispensing manner so as to secure the retaining ring 4 to the lens barrel 1.
In the aforementioned conventional lens assembly, the light-shielding members 3 disposed among the lenses 2 are able to block flare around the lenses 2. However, since the light-shielding members 3 are relatively small-sized and thin, dislocation during assembly is likely to occur, which adversely affects imaging quality. Moreover, the conventional lens assembly requires securing of the lenses 2 with the retaining ring 4 after the last one of the lenses 2 is mounted, followed by dispensing and curing the adhesive elements 5. The assembling procedures of the conventional lens assembly are relative complicated.
Referring to FIG. 2, another conventional lens assembly includes a lens barrel 6, a plurality of lenses mounted in the lens barrel 6, a plurality of light-shielding members 8 mounted among the lenses 7, and an adhesive element 9 for retaining the lenses 7 in the lens barrel 6. This conventional lens assembly differs from the abovementioned conventional lens assembly of FIG. 1 in the omission of the retaining ring (see FIG. 1) to be mounted after mounting of the last one of the lenses 7 (referred to as the last lens 7 hereinafter) in the lens barrel 6 is completed. The last lens 7 is directly bonded to the lens barrel 6 through the adhesive element 9 disposed at the interconnection area therebetween.
However, apart from the adverse effect on imaging due to dislocation of the light-shielding members 8 during assembly, coating of the adhesive element 9 tends to interfere with an effective optical path of the last lens 7 and there is still room for improvement in the lens assembly.